A three-story downtown office building on North Fourth Street near the Wisconsin Center will be demolished this month because of structural problems.

That demolition likely would result in the property becoming a parking lot.

The vacant building at 734 N. Fourth St. belongs to Mental Health America of Wisconsin, a nonprofit organization. Mental Health America moved from Fourth Street to the Tannery office building in Milwaukee years ago.

The Fourth Street office is functionally obsolete and structurally unsound, said Ryan Schultz, principal with HSI Properties LLC, Waukesha. Demolition is planned for this month, he said.

HSI Properties is listing the property for sale on behalf of Mental Health America, and is negotiating with a company that may buy it to operate a surface parking lot on the property, Schultz said. Spaces in the lot would be used by people working in nearby office buildings, he said.